It is quite important to get familiar with the GPS terminology. There are few terms which are commonly used and you must get familiar with them before you buy a GPS. They are:

Waypoints: These are just some important landmarks on your way. These landmarks then help you in your navigation. These waypoints can be any important crossing or just any other minor references like a broken tree or a rock etc.

How the waypoint is stored? Waypoints can be stored in two ways. You can take the coordinated from your map and store it. This is usually done before leaving your office or home. You can also enter the waypoint coordinates directly on to your GPS unit.

What is bearing and how different it is from heading? The course you aim at is bearing and the one on which you are actually on is heading. However they may differ due to some obstacles like rocks, fences etc.

TTFF: This is the time taken by the satellites to fix to obtain a complete fix. This is required for fixing the position. TTFF stands for Time To First Fix.

Route: It is waypoints entered in a particular order.

Channel Receivers: there are 8 channel receivers and 12 channel receivers. The 12 channel receiver can receiver signals from 12 satellites whereas 8 channel receiver receives signals from 8 satellites.

WAAS: It is Wide Area Augmentation System. This system of satellites is used for giving correct GPS signals. This satellite system is present in North America. South America also has these signals; however they are not very accurate. WAAS works best in wide open spaces and also with marine applications.